Recently, new MIT application techniques have been developed. It is generally known that a discontinuous jump occurs at 68° C. in vanadium oxide (V2O5), and thus a ceramic material of vanadium oxide generating a discontinuous MIT can be used as a sensor for sensing a specific temperature. However, a new fact that a discontinuous MIT can be controlled was discovered and disclosed in the paper, ‘New J. Phys. 6 (2004) 52 (www.njp.org)’.
Sensors are generally classified into a physical quantity sensor sensing light, magnetism, pressure and so on and a chemical quantity sensor sensing a gas, timidity and so on. As technology is being continuously developed, a variety of accurate sensors are being developed.
Among sensors are temperature sensors that use a thermistor or a bimetal. The temperature range that can be sensed by the temperature sensors is limited to a specific temperature or may be excessively wide. Sensors sensing the intensity of light include a Charge Coupled Device (CCD) image sensor and a Complementary Metal Oxide Semiconductor (CMOS) image sensor used for digital cameras or camcorders. These sensors are expensive and capable of sensing only light.
In an MIT element, an abrupt transition from an insulator to a metal occurs at a specific voltage (referred to as ‘transition voltage’ hereinafter) or at a specific temperature (referred to as ‘transition temperature’ hereinafter). The transition voltage or the transition temperature can be controlled, as described above. MIT phenomenon can be explained, using a voltage-current curve, as a discontinuous jump of current at the transition voltage or the transition temperature. The transition voltage or the transition temperature of the MIT element can vary according to an external factor such as light, temperature, pressure or a gas. Thus, a variation in an external factor can be sensed by continuously measuring a discontinuous MIT jump of the MIT element. However, an electronic circuit capable of measuring the discontinuous MIT of the MIT element has not yet been developed.